1. Field of Art
The present invention relates to measuring audience viewership, and more particularly, to accurately measuring audience viewership of an online live broadcast program provided through a communication network.
2. Description of Art
Various programs are broadcast over various broadcasting systems including an over-the-air broadcasting system, a cable broadcasting system, and a satellite broadcasting system. The Internet has recently emerged as a medium for online live broadcasting of programs to viewers. In the online live broadcast services, scenes of live events are captured by a camera and streamed to the viewers through the Internet in real time. Programs available over-the-air broadcasting or cable broadcasting may also be streamed to the users via the Internet.
In the online live broadcast services, an audience viewership survey may be performed to collect the users' preference, liking or disliking of a program in a manner similar to what is done for over-the-air broadcasting. To measure audience viewership for live over-the-air broadcasting, a survey is performed on sample audiences using telephone interviews in which surveyors call and interview the sample audiences. Surveyors record answers from the sample audiences watching the broadcasted program at certain times of the day and tally the answers to obtain the audience viewership. Such method of calling and interviewing the audiences takes a long time and incurs a large amount of cost because individual phone calls must be made and conducted by the surveyors. Further, the limited number of sample audiences results in a wider margin of errors and inaccurate audience viewership measurements.
For programs broadcast over the Internet, the audience viewership may be determined using the number of transmission requests for the content item through the Internet. This method is widely used in measuring audience viewership for programs broadcast over the Internet. Unlike the online broadcast of content items stored in advance and later transmitted to the users, the viewership of the streamed programs through the Internet in real time are often measured with respect to a specific point of time.
In the online live broadcast programs covering live events are captured by a camera, encoded, and then transmitted to the users through the Internet. Due to the delay associated with the encoding, transmitting data packets, and the loading or the buffering of data, data packets of the programs may be processed at different times in different components of a broadcasting system. For example, assuming that a national soccer team scored a goal at 7:50 pm, the time at which the live broadcast data is completely encoded by an encoding server and then transmitted to the media server may be 7:51 pm. Data for the scoring scene may be transmitted to the users at a later time (e.g., 7:52 pm). Due to further delay associated with the transmission, the users may view the scoring scene at 7:53 pm. That is, the users of an online live broadcasting program may view a scene of a live event at a time that may lag behind the actual event by some amount of time.
The audience rating survey of the online live broadcast program, however, does not take into account the lag between the time for receiving the data and transmitting the data to the clients. Therefore, in the above-mentioned example, an inaccurate survey may be performed by collecting the viewership associated with the scoring scene at 7:50 pm (time when the national soccer team actually scored a goal) and not at 7:53 pm (time when the event was actually viewed by the users).
Conventionally, the audience rating survey of an online live broadcast program is made using the number of clients served with the live broadcast data represented by the number of transmissions of a web page associated with the program along with the time when the data are transmitted to the clients. However, the number of clients having received the live broadcast data or the page view information is included in the rating even when users erroneously access the web page or intentionally clicks to enhance the number of page views.